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1.
Luminescence ; 37(5): 828-836, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35293139

RESUMEN

Motivated by our previous study on Sm3+ ions as thermoluminescence (TL) sensitizers to the BaO-ZnO-LiF-B2 O3 -Yb2 O3 glass system, in the current study we examined the effect of Er3+ ion co-doping on the TL characteristics of this glass system. The 4f-4f electronic transitions of the Er3+ and Yb3+ ions were confirmed via the optical absorption spectrum. Notably, the use of Yb3+ -Er3+ ions failed to improve the TL intensity, sensitivity, and trap density. However, they enabled the glass system to function as an activator-quencher system. The linearity range and effective atomic number remained unaffected after co-doping. In addition, the problem of anomalous fading caused a remnant signal of just 58% after a week of storage of the Yb3+ monodoped glass. This was resolved by the optimum co-doping of Er3+ ions to achieve an 89% signal. The co-doping of Er3+ ions to the BaO-ZnO-LiF-B2 O3 -Yb2 O3 glass system regulated its thermal stability and therefore supplemented its potential for radiation monitoring in food processing and retrospective dosimetry.


Asunto(s)
Óxido de Zinc , Vidrio , Iones , Estudios Retrospectivos , Dosimetría Termoluminiscente
2.
Int J Mol Sci ; 23(4)2022 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-35216511

RESUMEN

The modification of chitosan represents a challenging task in obtaining biopolymeric materials with enhanced removal capacity for heavy metals. In the present work, the adsorption characteristics of chitosan modified with carboxyl groups (CTS-CAA) towards copper (II) and zinc (II) ions have been tested. The efficacy of the synthesis of CTS-CAA has been evaluated by studying various properties of the modified chitosan. Specifically, the functionalized chitosan has been characterized by using several techniques, including thermal analyses (differential scanning calorimetry and thermogravimetry), spectroscopies (FT-IR, XRD), elemental analysis, and scanning electron microscopy. The kinetics and the adsorption isotherms of CTS-CAA towards both Cu (II) and Zn (II) have been determined in the aqueous solvent under variable pH. The obtained results have been analyzed by using different adsorption models. In addition, the experiments have been conducted at variable temperatures to explore the thermodynamics of the adsorption process. The regeneration of CTS-CAA has been investigated by studying the desorption process using different eluents. This paper reports an efficient protocol to synthesize chitosan-based material perspective as regenerative adsorbents for heavy metals.


Asunto(s)
Materiales Biocompatibles/química , Quitosano/química , Cobre/química , Iones/química , Agua/química , Zinc/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Termodinámica , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
3.
Int J Mol Sci ; 23(15)2022 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-35955812

RESUMEN

Spent Ni-Cd batteries are now considered an important source for many valuable metals. The recovery of cadmium, cobalt, and nickel from spent Ni-Cd Batteries has been performed in this study. The optimum leaching process was achieved using 20% H2SO4, solid/liquid (S/L) 1/5 at 80 °C for 6 h. The leaching efficiency of Fe, Cd, and Co was nearly 100%, whereas the leaching efficiency of Ni was 95%. The recovery of the concerned elements was attained using successive different separation techniques. Cd(II) ions were extracted by a solvent, namely, Adogen® 464, and precipitated as CdS with 0.5% Na2S solution at pH of 1.25 and room temperature. The extraction process corresponded to pseudo-2nd-order. The prepared PTU-MS silica was applied for adsorption of Co(II) ions from aqueous solution, while the desorption process was performed using 0.3 M H2SO4. Cobalt was precipitated at pH 9.0 as Co(OH)2 using NH4OH. The kinetic and thermodynamic parameters were also investigated. Nickel was directly precipitated at pH 8.25 using a 10% NaOH solution at ambient temperature. FTIR, SEM, and EDX confirm the structure of the products.


Asunto(s)
Cadmio , Níquel , Cadmio/química , Cobalto , Suministros de Energía Eléctrica , Níquel/química , Dióxido de Silicio
4.
J Xray Sci Technol ; 29(2): 373-382, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33554936

RESUMEN

The main objective of this work is to explore the X-ray interaction properties of P2O5- SnCl2-SnO bioactive glass system using Photon Shielding and Dosimetry (Phys-X/PSD) software in the energy range 10-150 keV. The study of these parameters will have applications in various fields of nuclear medicine, medical technology, and other medical applications. The value of mass attenuation coefficients (µm) and effective atomic numbers (Zeff) decrease whereas the value of mean free path as well as half value layer increases with rises in energy in the selected energy range. The study results indicate that bioactive glass composition of T2 of chemical composition (35P2O5- 55SnCl2-10SnO) possesses the lowest value of mean free path (MFP), and highest value of µm, and Zeff, among the chemical composition.


Asunto(s)
Fotones , Radiometría , Compuestos de Fósforo , Radiografía , Rayos X
5.
Ceram Int ; 46(16): 25671-25677, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32836654

RESUMEN

In this paper, we used Geant4 Monte Carlo simulations to investigate the effect of TiO2/V2O5 substitution on the radiation shielding properties of alkali borate glasses in the chemical form of 30Li2O+55B2O3+5ZnO + xTiO2+(10 - x)V2O5, where x = 0, 2.5, 5, 7.5, and 10 mol%. Also, the optical properties were examined by evaluating several factors such as molar refraction (Rm), metallization criterion (M), molar polarizability (αm), dielectric coefficients (static and optical), optical transmission (T), and reflection loss (RL). The radiation shielding properties of the tested glasses were estimated by determining the mass attenuation coefficient, and other related factors such as the tenth value layer (TVL), the mean free path (MFP), the electron total stopping powers (Ψe) and the electron continuous slowing down approximation range (CSDA) (Φe) for different energy values. The results of Geant4 Monte Carlo were compared with the theoretical values calculated by XCOM platform. The results revealed that the TiO2/V2O5 substitution had a remarkable influence on the gamma shielding properties for the tested glasses. On the other hand, the optical properties slightly changed by the TiO2/V2O5 substitution. The gamma shielding properties of the tested glasses were compared with many samples in terms of MFP. The present glasses showed superior features to apply for optical and radiation shielding applications.

6.
J Radiol Prot ; 38(4): 1321-1343, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30113314

RESUMEN

Radiotherapy is one of the commonly used treatments for cancer. A compensator is a device used in intensity modulated radiotherapy (IMRT) treatments to compensate for the irregularities of the body. One can provide a more uniform distribution of dose for the treatment of tumors using compensators in IMRT to obtain a better therapeutic outcome. A variety of compensators are used in IMRT. One high Z (cerrobend), two medium Z (brass and steel) and one low Z (lucite) compensators are selected for the present study. The mass attenuation coefficients have been computed in an energy range of 15 keV to 15 MeV using XCOM program and the Monte Carlo N-particle-5 (MCNP5) code. The percentage deviation between the values indicates that the mass attenuation coefficients obtained using both the methods are in good agreement. These values are further used to calculate the linear attenuation coefficients, mass energy absorption coefficients, effective atomic numbers, electron densities, equivalent atomic numbers and energy absorption and exposure buildup factors. All these parameters have been calculated in the energy range of 0.015-15.0 MeV. The variation of parameters has been studied with incident photon energies, chemical composition and penetration depth of the various compensators. It is observed that up to 3 MeV and 14 mean free path (mfp): compensator with lowest values of the effective atomic numbers has the highest value of the buildup factor. Cerrobend has a particularly high value of the buildup factor near 100 keV. Above 3 MeV and 14 mfp: compensator with lowest values of the effective atomic numbers has the lowest value of the buildup factor. Thus a complete reversal in trend is observed at 3 MeV and 14 mfp. All these observation have been explained due to the dominance of the different interaction processes in different energy regions.


Asunto(s)
Método de Montecarlo , Neoplasias/radioterapia , Radiometría , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/métodos , Simulación por Computador , Humanos
7.
Nanoscale Adv ; 6(2): 548-558, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38235071

RESUMEN

Improving the role of electron-transport layers (ETLs) in carbon-based perovskite solar cells (CPSCs) is a promising method to increase their photovoltaic efficiency. Herein, we employed rGO sheets decorated with ZrO2 nanoparticles to increase the electron transport capability of mesoporous TiO2 ETLs. We found that the rGO/ZrO2 dopant enhanced the conductivity of the ETL, reducing the charge-transfer resistance at the ETL/perovskite interface and reducing charge recombination in the corresponding CPSCs. Notably, this dopant did not effectively change the transparency of ETLs, while increasing the light-harvesting ability of their own top perovskite layer by improving the crystallinity of the perovskite layer. The rGO/ZrO2-containing ETLs produced a champion efficiency of 15.21%, while devices with a net ETL recorded a maximum efficiency of 11.88%. In addition, the modified devices showed a higher stability behavior against ambient air than the net devices, which was linked to the passivated grain boundaries of the modified perovskite layers along with the improved hydrophobicity.

8.
Artículo en Inglés | MEDLINE | ID: mdl-38183543

RESUMEN

Corrosion is a pervasive issue with significant economic and safety implications across various industries. Nanoceramic-based coatings have emerged as a promising solution for corrosion protection due to their unique properties and mechanisms. This review aims to comprehensively examine the synthesis, mechanisms, and applications of nanoceramic-based coatings for corrosion protection. The review begins by highlighting the importance of corrosion protection and its impact on different industries. It introduces nanoceramic-based coatings as a potential solution to address this challenge. The objective is to provide a thorough understanding of the synthesis methods, mechanisms, and applications of these coatings. The fundamental principles of corrosion and different corrosion mechanisms are discussed, along with the limitations of traditional corrosion protection methods. The review emphasizes how nanoceramic-based coatings can overcome these limitations and provide superior corrosion resistance. Various synthesis methods, including sol-gel, electrodeposition, and physical vapor deposition, are described in detail, along with the factors influencing the synthesis process. Recent advancements and innovations in nanoceramic coating synthesis techniques are also highlighted. This looks at how coatings made with tiny ceramic particles protect against corrosion. It examines the importance of small-scale details like particle size, shape, and what the particles are made of. The formation of passive layers, self-healing mechanisms, and barrier properties of nanoceramic coatings are explained. The diverse applications of nanoceramic coatings for corrosion protection in industries such as automotive, aerospace, and marine are comprehensively discussed. Case studies and examples demonstrating the significant corrosion resistance and improved performance achieved with nanoceramic coatings are presented.

9.
Sci Rep ; 14(1): 14891, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38937501

RESUMEN

Aiming to extend the scope of utilizing glass in radiation shielding, this work investigates the radiation interaction response of a borate-based glass system. Four borate-glass samples of different substituting concentrations of calcium oxide ( 70 - x )B2O3: 10 Na2O : 5 Al2O3 : 15 BaO: x CaO were prepared. To assess the shielding performance of the prepared glass samples, a high-purity germanium detector and different radioactive sources (different energies) were used. Via the narrow beam method, the linear attenuation coefficients (LACs) were experimentally measured. So, the transmission factor (TF), the half-value layer (HVL), the tenth value layer (TVL), the mean free path (MFP), and the radiation protection efficiency (RPE) were calculated for all prepared samples. It was observed that the increase of the concentration of calcium oxide in the proposed borate-based glass samples leads to improve their performance in shielding against radiation. At low energy, the RPE of the samples is almost 100%. However, it was observed that as energy of the radiation source increases, the shielding performance of the samples will decrease. High energy dependence was found when calculating TF, HVL, TVL, and MFP. They were increased with the increase of the energy of the incident photons. At 0.662 MeV, the TF values are equal to 79.26, 79.00, 79.72, and 78.43% for BNABC-1, BNABC-2, BNABC-3, and BNABC-4 in the same oder, respectively. The application of the proposed composition of borate-based glass as a transparent shield against low-energy ionizing radiation was highlighted.

10.
Appl Radiat Isot ; 206: 111195, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38280278

RESUMEN

A series of ceramic samples fabricated based on ZnO doped different concentrations of natural clay according to the relation (1-x) ZnO - (x) clay; 5 wt% ≤ x ≤ 20 wt%. The samples were pressed and sintered at 1200 °C. The experimental techniques were used to characterize and measure the chemical composition, density, and current-voltage measurements for the fabricated ceramics samples. The measurements depict an increase in the I-V nonlinearity with raising the clay concentration, where the increase in clay by up to 20 wt% shifts breakdown voltage to a higher value of up to 390 V/cm and decreases leakage current to 55 mA/cm2. The examinations for the gamma-ray shielding capacity for the fabricated composites (utilizing Monte Carlo simulation) demonstrate enrichment of clay concentration between 5 wt% and 20 wt% reduced the linear attenuation coefficient for the fabricated ceramics by 23.15% and 8.66% at γ photon energy of 0.059 MeV and 1.252 MeV, respectively. The half-value thickness and lead's equivalent thickness increased along with a drop in the linear attenuation coefficient, but the radiation protection effectiveness of the fabricated ceramics increased.

11.
Sci Rep ; 14(1): 5429, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38443496

RESUMEN

The current work deals with the synthesis of a new glass series with a chemical formula of 5Al2O3-25PbO-10SiO2-(60-x) B2O3-xBaO; x was represented as 5, 10, 15, and 20 mol%. The FT-IR spectroscopy was used to present the structural modification by rising the BaO concentration within the synthesized glasses. Furthermore, the impacts of BaO substitution for B2O3 on the fabricated borosilicate glasses were investigated using the Makishima-Mackenzie model. Besides, the role of BaO in enhancing the gamma-ray shielding properties of the fabricated boro-silicate glasses was examined utilizing the Monte Carlo simulation. The mechanical properties evaluation depicts a reduction in the mechanical moduli (Young, bulk, shear, and longitudinal) by the rising of the Ba/B ratio in the fabricated glasses. Simultaneously, the micro-hardness boro-silicate glasses was reduced from 4.49 to 4.12 GPa by increasing the Ba2+/B3+ ratio from 0.58 to 3.18, respectively. In contrast, the increase in the Ba/B ratio increases the linear attenuation coefficient, where it is enhanced between 0.409 and 0.448 cm-1 by rising the Ba2+/B3+ ratio from 0.58 to 3.18, respectively. The enhancement in linear attenuation coefficient decreases the half-value thickness from 1.69 to 1.55 cm and the equivalent thickness of lead is also reduced from 3.04 to 2.78 cm, at a gamma-ray energy of 0.662 MeV. The study shows that the increase in the Ba2+/B3+ ratio enhances the radiation shielding capacity of the fabricated glasses however, it slightly degrades the mechanical properties of the fabricated glasses. Therefore, glasses with high ratios of Ba2+/B3+ have high gamma-ray shielding ability to be used in hospitals as a shielding material.

12.
Heliyon ; 10(7): e28646, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38586325

RESUMEN

The structural and electronic properties of ReS2 different forms - three-dimensional bulk and two-dimensional monolayer - were studied within density functional theory and pseudopotentials. A method for standardizing the description of bulk unit cells and "artificial" slab unit cells for DFT research has been proposed. The preference of this method for studying zone dispersion has been shown. The influence of the vacuum layer thickness on specified special high-symmetry points is discussed. Electron band dispersion in both classical 3D Brillouin zones and transition to 2D Brillouin zones in the proposed two-dimensional approach using the Niggli form of the unit cell was compared. The proposed two-dimensional approach is preferable for low-symmetry layered crystals such as ReS2. It was established that the bulk ReS2 is a direct gap semiconductor (band gap of 1.20 eV), with the direct transition lying in the X point of the first Brillouin zone, and it is in good agreement with published experimental data. The reduction in material dimension from bulk to monolayer was conducted with an increasing band gap up to 1.45 eV, with a moving direct transition towards the Brillouin zone center. The monolayer of ReS2 is a direct-gap semiconductor in a wide range of temperatures, excluding only a narrow range at low temperatures, where it comes as a quasi-direct gap semiconductor. The transition, situated directly in the Γ-point, lies 3.3 meV below the first direct transition located near this point. The electronic density of states of ReS2 in the bulk and monolayer cases of ReS2 were analyzed. The molecular orbitals were built for both types of ReS2 structures as well as the electron difference density maps. For all types of ReS2 structures, an analysis of populations according to Mulliken and Voronoi was carried out. All calculated data is discussed in the context of weak quantum confinement in the 2D case.

13.
Appl Radiat Isot ; 212: 111457, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39068692

RESUMEN

In clinical settings, standard dosimeters might miss radiation mishaps. Retrospective dosimeters could help to track personnel (such as patients and other staff who don't wear dosimeters) exceeding safe limits and assess long-term exposure trends. This study has investigated key thermoluminescence (TL) dosimetric characteristics, including the glow curve structure, dose-response, energy dependence, sensitivity and fading of various safety glasses that are used as screen protectors of smartphones subjected to photon irradiation. Among the studied glasses, the HD Anti-Peep safety glass for iPhone has been found to exhibit a linear dose-response with a regression coefficient of 99% within the dose range of 2-10 Gy. Moreover, all the safety glasses showed independence with respect to photon energy of 6 MV and 10 MV. The TL glow curves of the samples showed a broad glow peak between 125 °C and 325 °C at 10 Gy. The TL kinetic parameters of the safety glasses were also studied by analyzing the glow curves using the peak shape and initial rise method. The geometric factor (µg) is found to be within the range of 0.43-0.53, which indicates the suitability of applying Chen's general-order formula to calculate the kinetic parameters such as activation energy, frequency factor and trap lifetime. The activation energy (E) and frequency factor (s) are found in the range of 0.31-0.54 eV and 4.55 × 103 to 2.12 × 106 s-1 respectively obtained via the peak shape method. The relatively long trap lifetime and observed thermoluminescence features indicate that the HD Anti-Peep safety glass offers a better option to estimate dose retrospectively to ensure the safety of human health.

14.
Sci Rep ; 13(1): 8936, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37264111

RESUMEN

Cobalt-doped titania nanocomposites were fabricated to be utilized for radiation shielding aims. The chemical composition of the composites was measured using the energy-dispersive X-ray spectrometer. Moreover, the structure of the composites was evaluated using the X-ray diffractometer, and the morphology of the fabricated composites was presented using the scanning electron microscope. Furthermore, the γ-ray shielding properties were estimated using the Monte Carlo simulation between 0.059 and 2.506 MeV. The linear attenuation coefficient of the fabricated composites decreased by factors of 93% for all samples by raising the incident γ-energy between 0.059 and 2.506 MeV. Moreover, the partial replacement of the Ti4+ by Co3+ slightly enhanced the linear attenuation coefficient from 0.607 to 0.630 cm-1 when the Co3+ increased from 0 to 3.7 wt%. The improvement in the linear attenuation coefficient causes an enhancement in other radiation shielding properties.

15.
Sci Rep ; 13(1): 18429, 2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37891224

RESUMEN

With the use of multilayer materials such as concrete, mortar and ceramics that were fortified with PbO, WO3 and Bi2O3 nanoparticles, our study's objective was to produce a an effective photon shielding system. Experimental evaluation of the radiation shielding efficiency of two sets of samples with various thicknesses was conducted. The elemental content and morphology of the samples were corroborated by SEM and EDX studies, with ceramic samples exhibiting superior particle distribution and fewer voids than concrete and mortar specimens. The linear attenuation coefficient (LAC) was studied both experimentally and numerically using the Phy-X program, and it was found that the two sets of values were in satisfactory agreement. The values of LAC were consistently greater for samples with 30% of the selected heavy metal oxides than for those with 10%. The LAC for Cer-1 was 5.003 cm-1 at 0.059 MeV, whereas the corresponding LAC for Cer-2 was 2.123 cm-1. The LAC values were as follows: ceramics (5.003 cm-1), mortar (2.999 cm-1), concrete (2.733 cm-1), and the transmission factor (TF) examination of the multiple-layer specimens showed that the TF of the 3 cm thick multilayer sample was lower than that of the 2 cm thick sample and that both multilayer samples displayed better attenuation efficiency in comparison to single-layer specimens. The results show the possibility for employing multilayer structures with different densities, thicknesses, and sizes in suitable radiation shielding applications.

16.
Heliyon ; 9(9): e19364, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37681126

RESUMEN

Zirconium-lithium-phosphate glasses were elaborated through the melting-quenching technique. The primary objective of this research is to investigate how the replacement of lithium oxide with zirconium oxide impacts the physical, thermal, mechanical, and electrical properties of the fabricated glasses. The result showed that the vitreous materials were obtained with a ZrO2 content lower than 1 mol%. Furthermore, it is found that incorporating ZrO2 in the glassy phosphate framework affects mal compatibility and increases the durability of the glassy samples. Analyzing the mechanical performance reveals that the incorporation of ZrO2 leads to enhancements in the elastic constants of the glasses, including the longitudinal modulus, shear modulus, Young's modulus, bulk modulus, and Poisson coefficient. The bond strengths are used to calculate and explain the glasses' Vickers hardness values. On the other hand, the infrared (IR) spectroscopy results reveal that replacing Li2O with ZrO2 oxide in the glassy matrix causes significant structural changes. Finally, the dielectric features of the prepared glasses versus frequency and temperature are analyzed. The significance lies in the fact that the replacement of lithium with zirconium leads to a reduction in the ionic conductivity of the glasses.

17.
Heliyon ; 9(5): e15906, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37215796

RESUMEN

This paper reports an intense up-conversion luminescence from Dy3+-doped strontium-telluro-alumino-magnesium-borate glasses for the first time. The samples were made via the melt-quenching method and characterized to determine the influence of various CuO nanoparticles contents change on their up-conversion emission traits. Absorption spectral data were used to calculate the Judd-Ofelt intensity parameters. The sample without CuO nanoparticles revealed two intense photoluminescence up-conversion emission peaks at 478 and 570 nm. In addition, CuO nanoparticles-activated sample displayed about 1.4-fold up-conversion emission intensity improvement due to strong light absorption in the visible to the infrared region at 799 nm excitation. The stimulated emission cross-section of the CuO nanoparticles-activated glasses was increased from 102.4 × 10-23 to 1301.1 × 10-23 cm2 (nearly 10-fold amplification) while the branching ratio was reduced to 66.9%. Thus, CuO nanoparticles as an additive in the current glass matrix enhanced the up-conversion emission and strengthened the associated nonlinear optical properties. CIE 1931 color matching revealed the influence of CuO in modifying the up-conversion color coordinates, thereby improving the white color purity. The achieved up-conversion emission coupled with the color tunability of the proposed glasses may be advantageous for the up-conversion UV tunable laser making.

18.
Heliyon ; 9(10): e20262, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37767474

RESUMEN

The demand for new glass hosts with emergent properties is constantly growing for various miniaturized applications. Thus, some new types of Sm2O3-activated strontium-telluro-alumino-magnesium-borate glasses with copper oxide nanoparticles (CuONps) insertion were made using melt-quenching approach. The obtained glasses were characterized to determine the effects of Sm2O3 concentration changes on their thermal, structural, and luminescence properties. XRD, FTIR, and HRTEM analyses of the samples verified their glassy nature, presence of different functional units and CuONps, respectively. DTA analysis showed excellent thermal stability of these glasses with a stability factor as much as 125 °C. The optical absorption properties of the glasses were highly sensitive to Sm3+ concentrations variation. The Judd-Ofelt intensity parameters of the glasses with and without CuONps followed the trend of Ω6˃Ω4˃Ω2 and Ω4˃Ω6˃Ω2, respectively. These glasses displayed 4 visible luminescence bands at 561, 598, 645, and 705 nm corresponding to 4G5/2 â†’ 6H5/2, 4G5/2 â†’ 6H7/2, 4G5/2 â†’ 6H9/2, and 4G5/2 â†’ 6H11/2 transitions in Sm3+. In addition, branching ratio above 80% and stimulated emission cross-section up to 135.82 × 10-23 cm2 were achieved. The stimulated emission cross-section and optical gain were enhanced due to the inclusion of CuONps in the glasses. These glasses may be useful for solid state laser and optical amplifier development.

19.
Appl Radiat Isot ; 192: 110600, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36473320

RESUMEN

The purpose of this study is to examine the clinical radiation effects on patients with various stents. Several previous researches focused on the mechanical and physical features of the stents, but there have been few studies that focus on the interaction with radiological and clinical radiation. For stent material analysis, the ANSYS package program was employed. These materials and models are often built in three dimensions for three different types of stents made of three various materials. Estimates of blood pressure and thermal radiation were explored, as were the effects of non-ionizing radiation. Furthermore, the radiation attenuation characteristics of stent samples are investigated. The mass attenuation coefficient values are computed using MATLAB code over a large energy range of 0.015-15 MeV, and the findings are validated using theoretical WinXCom results. To determine the gamma-ray attenuation performances of the studied stent samples, variables such as the mass attenuation coefficient (MAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic number (Zeff), exposure build-up factor (EBF), and energy absorption build-up factor (EABF) are computed. Effective removal cross-sections (ΣR) of stent samples were acquired to determine the capacity of stent samples to stop fast neutrons. Finally, the ability of stent samples to stop charged alpha and proton particles was evaluated utilizing mass stopping power and projected range parameters. The discovery demonstrates that S3 has the best attenuation as well as the best proton, alpha, and gamma radiation attenuation capability.


Asunto(s)
Protones , Stents , Humanos , Rayos gamma
20.
RSC Adv ; 13(18): 12554-12571, 2023 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-37101948

RESUMEN

Density Functional Theory (DFT) was employed to investigate the interaction between cyanogen chloride (ClCN) and the surface of a carbon nanocone (CNC). The findings of this research revealed that pristine CNC is not an ideal material to detect ClCN gas due to its minimal alterations in electronic properties. In order to enhance the properties of carbon nanocones, multiple methods were implemented. These included functionalizing the nanocones with pyridinol (Pyr) and pyridinol oxide (PyrO) as well as decorating them with metals such as boron (B), aluminium (Al) and gallium (Ga). Additionally, the nanocones were also doped with the same third-group metal (B, Al and Ga). The simulation results indicated that doping it with aluminium and gallium atoms yielded promising results. After a comprehensive optimization process, two stable configurations were obtained between the ClCN gas and the CNC-Al, and CNC-Ga structures (configurations S21, and S22) with E ads values of -29.11, and -23.70 kcal mol-1 respectively, using M06-2X/6-311G(d) level. The adsorption of ClCN on CNC-Al and CNC-Ga surfaces leads to a marked alteration in the electrical properties of these structures. Calculations reveal that the energy gap between the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) levels (E g) of these configurations increased in the range of 9.03% and 12.54%, respectively, thereby giving off a chemical signal. An analysis conducted by the NCI confirms that there is a strong interaction between ClCN and Al and Ga atoms in CNC-Al and CNC-Ga structures, which is represented by the red color in the RDG isosurfaces. Additionally, the NBO charge analysis reveals that significant charge transfer is present in S21 and S22 configurations (190 and 191 |me|, respectively). These findings suggest that the adsorption of ClCN on these surfaces impacts the electron-hole interaction, which subsequently alters the electrical properties of the structures. Based on the DFT results, the CNC-Al and CNC-Ga structures, which have been doped with aluminium and gallium atoms, respectively, have the potential to serve as good candidates for detecting ClCN gas. Among these two structures, the CNC-Ga structure emerged as the most desirable one for this purpose.

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